Removal Of Floral Buds Research Articles

Response of bt cotton to early season floral bud removal: Growth and Yield Distribution

Response of Bt cotton to square removal was studied to determine the impact of loss of fruiting forms due to insect pest attack or physiological damage on phenology, growth and yield of cotton at Punjab Agricultural University, Ludhiana, India. Three Bt cotton hybrids were assessed for the removal of floral buds for consecutive four weeks @ 25% and 50% from the day squares start initiation. The vegetative growth (plant height) in 25% and 50% square removal treatments increased significantly (˂0.0001) over that of undamaged control treatment among all the hybrids. In contrast, the reproductive growth (number of squares, flowers, bolls per plant and seed cotton yield) significantly decreased in 50% simulation treatments over that of undamaged control treatment and 25% square removal treatment in different hybrids. The decrease in seed cotton yield was 8.6 and 10.4% as compared to 0 and 25% square removal treatments, respectively. The results indicate that Bt cotton can tolerate at least modest levels (25%) of square removal without yield reduction.

How do sink and source activities influence the reproduction and vegetative growth of spring ephemeral herbs under different light conditions?

Spring ephemeral herbs inhabiting deciduous forests commonly complete reproduction and vegetative growth before canopy closure in early summer. Effects of shading by early canopy closure on reproductive output and vegetative growth, however, may vary depending on the seasonal allocation patterns of photosynthetic products between current reproduction and storage for future growth in each species. To clarify the effects of sink-source balance on seed production and bulb growth in a spring ephemeral herb, Gagea lutea, we performed a bract removal treatment (source reduction) and a floral-bud removal treatment (sink reduction) under canopy and open conditions. Leaf carbon fixations did not differ between the forest and open sites and among treatments. Bract carbon fixations were also similar between sites but tended to decrease when floral buds were removed. Seed production was higher under open condition but decreased by the bract-removal treatment under both light conditions. In contrast, bulb growth was independent of light conditions and the bract-removal treatment but increased greatly by the bud-removal treatment. Therefore, leaves and bracts acted as specialized source organs for vegetative and reproductive functions, respectively, but photosynthetic products by bracts were flexibly used for bulb growth when plants failed to set fruits. Extension of bright period was advantageous for seed production (i.e., source limited) but not for vegetative growth (i.e., sink limited) in this species.

Photosynthetic compensation by the reproductive structures in the spring ephemeral Gagea lutea

Growth and reproduction of spring ephemerals inhabiting deciduous forests progress simultaneously during a short period from snowmelt to canopy closure. To clarify the mechanism to mitigate the cost of reproduction, contributions of foliar and non-foliar photosynthetic products to seed production were examined in a spring ephemeral Gagea lutea. Leaf growth, foliar and non-foliar photosynthetic activities, and total assimilated products were compared among reproductive-intact, floral bud-removal, and vegetative plants. Translocation of current photosynthetic products to individual organs was quantified by 13CO2-trace experiment. Bulb growth was compared between hand-pollination and floral bud-removal treatments. Finally, seed set was compared between intact, leaf-clipping, and bract-clipping treatments. Fruit-forming plants retained leaves longer than vegetative and floral bud-removal plants, but the assimilative contribution of extended leaf longevity was negligible. Carbon supply by bract photosynthesis was large enough for fruit development, while carbon supply by fruit photosynthesis was offset by the high respiration loss. Foliar photosynthetic products were largely transported to bulbs, while translocation to reproductive functions was negligible. Because the floral bud-removal increased the bulb growth, lack of reproduction could lead to more storage. The leaf-clipping had no effect on seed production, while the bract-clipping significantly reduced the seed production. Therefore, current photosynthesis of leafy bracts might be a major carbon source for fruit development. This self-compensative mechanism of reproductive structure enables the continuous reproductive activity in this species.

Population demographics and trade-offs to reproduction of an invasive and noninvasive species of Rubus

Do trade-offs between growth and reproduction differ between an invasive and noninvasive plant species and how do such trade-offs relate to population demographics? To help address these questions, we compared demographics for an invasive plant species, Rubus discolor, with a noninvasive congener, R. ursinus, in several populations of varying density. Removal of floral buds from reproductive canes increased the size of juvenile canes that arose from clonal sprouting in R. ursinus, suggesting a trade-off between current reproduction and growth. Removal of floral buds had no effect on growth of R. discolor. R. ursinus displayed trade-offs between reproduction (sexual and vegetative) and future growth based on negative correlations between leaf area production and both clonal sprouting and seedling production during the previous year. R. discolor did not exhibit these trade-offs. Both species had high population growth rates in low-density populations, but exhibited little or no growth in high-density populations. A life table response experiment was used to determine the underlying cause for the effect of density on population growth. For R. ursinus, lack of population growth in high-density populations was due primarily to increased mortality of clonally sprouting canes, while for R. discolor, it was due to decreased clonal cane production. Elasticity analysis revealed that clonal growth was more important than sexual reproduction for population growth of both species. However, elasticity values for sexual reproduction in R. discolor were greater in high- than low-density populations. This suggests an increased reliance on sexual reproduction in populations that had reached stable sizes, which could increase the capacity of R. discolor to disperse to new sites. Elasticity analyses were also used to simulate the efficacy of various control strategies for R. discolor. Control of this species could be attained by reducing clonal production within existing populations while reducing seed production to limit establishment of new populations.

Spatial Yield Distribution in Cotton Following Early‐Season Floral Bud Removal

A better understanding of cotton (Gossypium hirsutum L.) compensatory growth after loss of early‐season floral buds requires an assessment of the actual patterns of spatial yield distribution in damaged and undamaged plants. This study was conducted to determine if spatial yield distribution or yield components are altered in cotton in response to removal of early‐season floral buds. Beginning with the second week of squaring, floral buds were removed by hand for one, two, or three consecutive weeks. At 90 d after planting, plant height, leaf area index, main stem node number, fruit present, total fruiting positions, and dry weights were measured. The contribution to total yield from each fruiting position was determined at crop maturity. Results from this study show the lowest level of floral bud removal resulted in no differences in spatial yield distribution. As the intensity of early‐season floral bud removal increased, however, the probability of harvesting a mature boll decreased in the lower canopy but increased in the upper canopy. Removal of floral buds resulted in fewer first sympodial position fruit but more third sympodial position fruit at harvest. Thus, early‐season removal of floral buds resulted in additional seed cotton production on more apical and distal fruiting positions. These modifications in spatial yield distribution adequately replaced those floral buds removed early in the season because total seed cotton yield was not different among the treatments at crop maturity.

Conditioning of Fasciation by Gibberellin and Genotype in Cotton (Gossypium hirsutum L.).

The round-leafed mutant cotton line L-501 developed fasciation of the upper stem when field grown in Central Asia. Fasciation co-segregated with the mutant gene for round leaves In.(l) Fasciation developed at the flowering stage, but removal of floral buds did not prevent fasciation. Fasciation in L-501 could be inhibited by the gibberellin (GA) biosynthesis inhibitor chlorocholine chloride or by fusicoccin. GA(3) application in the field induced fasciation in the mutant's parental line L-463, which has five-lobed leaves and does not normally develop fasciation. Fasciation did not develop in either line, even after GA(3) treatment, in UK glasshouse conditions.Key Words. Fasciation-Gibberellin-Gossypium-Leaf-shape-Mutanthttp://link.springer-ny.com/link/service/journals/00344/bibs/18n1p45.html

Floral Bud Removal from Specific Fruiting Positions in Cotton: Yield and Fiber Quality

Lint from cotton (Gossypium hirsutum L.) bolls produced on proximal fruiting positions (FP) is often longer and more mature than lint from distal FP sites. The objective of this research was to quantify the effects of proximal or distal floral bud removal on yield, yield distribution, yield components, and fiber properties. Cotton (cv. Deltapine 5415) was grown in the field near Stoneville, MS, in 1993 and 1994. From first square to late bloom, young squares (floral buds) were removed from selected positions twice weekly. The most proximal FP was designated FP1, the second most proximal FP was designated FP2, etc. The three treatments were (i) check (no removal), (ii) P1 (FP2, FP3, and greater squares removed), and (iii) P2, (FP1 and FP3 and greater squares removed). Averaged across years, a greater percentage of bolls (82 vs. 68%) and larger bolls (1.61 vs. 1.50 g lint boll−1) were found at FP1 on the P1 treatment than on the check. A greater percentage of bolls (42%) were found at FP2 on the P2 treatment, than in other treatments (10‐24%). Lint yield (all bolls) the check (1090 kg ha‐−1) was 11 and 28% greater than the P1 and P2 treatment, respectively. In contrast to yield, composite fiber micronaire, maturity, and wall thickness were significantly greater (5‐6%) in the P1 and P2 treatments than the check treatment. Fiber length and strength were unaffected by treatment. These results suggest that cotton may not be able to achieve its full yield potential if limited to one boll per main stem node. The increases in fiber properties were small and probably not economically important.

Leaf Maturity and Temperature Affect Removal of Floral Buds from Camellia Ethephon

The influence of temperature and leaf maturity on ethephon-promoted abscission was examined by simultaneously applying either ethylene (10.5 μl·liter-1) or ethephon (0 to 4 ml·liter-1) to potted Camellia plants at four constant temperatures (10 to 30C). The abscission rate (time to 50% abscission) and extent of abscission of leaves, and vegetative and floral buds was measured. Increased temperature promoted the rate and extent of ethephon-promoted abscission and increased ethylene-promoted abscission rate of all organs of Camelliu. Lower temperatures reduced the abscission rate after ethephon application more than that following ethylene application. Sensitivity to ethephon was greater for leaves on newly extending shoots, although once shoot elongation and leaf expansion had ceased, leaves became less sensitive. Ethephon sensitivity increased progressively with maturation over the following 2 years. Optimal thinning of floral buds. at low temperatures required high ethephon concentrations, while at high temperatures, low ethephon concentrations were optimal. The influence on abscission of the time of year when ethephon was applied, is suggested to be due to tissue maturity, which affects tissue ethylene sensitivity, and temperature, which affects ethylene release from ethephon and tissue response to ethylene. Chemical name used: (2-chloroethyl) phosphoric acid (ethephon).

Early Season Floral Bud Removal and Cotton Growth, Yield, and Fiber Quality

AbstractCotton (Gossypium hirsutum L.) has a capacity to partially compensate for the loss of floral buds (squares). A 2‐yr (1989 and 1990) field study was conducted to determine how growth, yield, and fiber quality traits of different genotypes were affected by early season square removal. Early developing squares were removed by hand, or were induced to abscise by ethephon [(2‐chloroethyl)phosphonic acid] application. Genotypes used were ‘DPL 50’, a normal leaf type, and three leaf type isolines of ‘MD 65–11’ (normal, okra, and super okra). Compared to the check, the ethephon application decreased plant height by as much as 11% early after application, but the treated plants ultimately exceeded the check by 5% in height, in 1990. The seasonal maximum vegetative dry weight and leaf area index (LAI) did not differ between treatments either year, though the ethephon treatment did increase mainstem node number to 26, compared to 24 nodes for the check. Lint yields did not differ between treatments in 1989, but the ethephon treatment yielded 7% less than the check in 1990. Ethephon application reduced boll size 7% each year, compared to the check. Fiber quality traits were not affected by treatments in 1989, but in 1990 micronaire, maturity, and cell wall thickness were decreased by 6% on fiber from the ethephon plots as compared to the check. This study demonstrated that cotton has potential to compensate for early square loss but did not suggest that early square removal consistently leads to improved yields or fiber quality.

Selective Removal of Floral Buds from Camellia with Ethephon

Six concentrations of ethephon were applied to plants of `Donation' and `Anticipation' Camellia (L.) at two times (late summer and autumn) and three times (late summer, autumn, and midwinter) of the year, respectively. Abscission of leaves and floral and vegetative buds was determined. Sensitivity to ethephon varied markedly among plant organs. Greater sensitivity of floral buds indicated that ethephon could be used to selectively remove these with minimal abscission of other plant organs. Proportion of abscised organs varied with cultivar and time of application. Chemical name used: (2-chloroethyl)phosphonic acid (ethephon).

Influence of Maturity and Fruit Yield on Susceptibility of Peanut to Cercosporidium personatum (Late Leafspot Pathogen)1

Abstract A positive relationship between both low pod yield and late maturity of peanut (Arachis hypogaea L.) with resistance to leafspot (Cercospora arachidicola Hori and Cercosporidium personatum (Berk & Curt.) Deighton) has been observed in breeding material and germplasm. To study this association, three peanut genotypes (Early Bunch, Florunner, and Dixie Runner) varying in maturity and yield potential were grown both with and without fungicide spray. Lower yield and later maturity treatments were further imposed on these genotypes through floral bud removal. Removal of floral buds resulted in less leafspot injury, as measured by lesion number per leaf or by a leaf retention score. There was a significant cultivar × treatment interaction. Removal of floral buds significantly reduced pod yield for Early Bunch. The use of chlorothalonil improved yields for Early Bunch and Florunner, but not for Dixie Runner. The proportion of sound mature kernels was increased in Florunner and decreased in Early Bunch by the floral bud removal treatment with no fungicide. Trends for yield of sound mature kernels were similar to those of pod yields. The improved resistance, delayed maturity, and lower yield of treatments with floral bud removal may explain the association noted among three traits in breeding material.

熱帯圃場条件における×<i>Aranda</i> Christine の摘芽による開花期の制御

The growth and flower production of×Aranda Christine cv. “130” grown under tropical field conditions were studied. On the average, an Aranda orchid produced 2-5 leaves and an increase of 7cm in height per month for the first 18 months after transplanting. Cut flower production was evident only 5 months later. Aranda has 3 major flower peaks-April, June and December. Cut flower production of×Aranda Christine could be successfully staggered by floral bud removal. Through bud removal, it is possible to shift the flower production peak for 2 weeks. No apparent effect of bud removal on flowering and flower quality was observed as the subsequent flowering behaviour was normal.

Effect of Early Season Square Removal on Three Leaf Types of Cotton1

In certain environments, reduced leaf‐open canopy cottons (Gossypium hirsutum L.) allow more light penetration and air circulation within their canopies than do normal leaf types. However, too much reduction in canopy can reduce overall productivity and economic yield. Removal of floral buds (squares) early in the season has been shown to result in larger plant size. Square removal was carried out in the field (fine‐silty, mixed, thermic, Aquic Fragiudalf soil type) on normal, okra, and super okra leaf type near‐isogenic lines of a ‘Stoneville 213’ background cotton for 3 and 6 weeks to determine i) if improved yield could be obtained in one or both open canopy types by enlarging the canopy and ii) if delaying fruit set produced differential responses in these leaf types. Results would form a basis for development of a boll weevil (Anthonomus grandis Boh.) trap crop system using exogenous chemicals to effect square abscission. Removal of squares increased plant height, leaf area index (LAI) and number of sympodial branches. The super okra leaf type produced the greatest responses to square removal. Fruit set was more rapid and occurred during a shorter interval for all leaf types undergoing square removal for 3 weeks, but the greatest response was obtained from super okra. Comprehensive analysis in 1983 indicated the rapid fruit set was due primarily to more sympodia fruiting simultaneously. The 3‐week treatment was more consistent in this response than the 6‐week treatment because of the generally shorter horizontal and vertical flowering intervals. Economic yield of normal and okra leaf types was generally not improved by square removal, whereas the super okra leaf type in the 3‐week square removal treatment produced an average 23.5% greater lint yield than its control. Differences in lint percentage were significant between treatments in 1981 with significant leaf type by treatment interactions in 1983. The data indicate that the super okra leaf type had the most consistent responses to 3 weeks of manual square removal. These results imply that this leaf type would produce the best response to exogenous chemical abscission of squares and the greatest chance of recovery from early season insect pressure.

Dwarfism Caused by Floral-Bud Removal in Petunia and its Reversal by Gibberellin

The effect of floral-bud removal at different stages of development on the plant height and on the total number of buds of Petunia was studied. Continuous removal of all the floral buds 2 d before anthesis caused a marked decrease in plant height and also increased the total number of floral buds formed thereafter. At other stages of floral bud development, bud removal had a lesser effect on both phenomena. Moreover, the plants did not respond to bud removal at anthesis. GA3 at 25 ppm applied to plants from which the buds had been removed, promoted stem elongation. The most pronounced effect was on plants from which the buds were removed 2 d before anthesis, but it had no effect on plants from which the buds were removed at anthesis stage. The possible involvement of endogenous growth hormones in the response of Petunia plants to floral-bud removal and to application of GA3 is discussed.

Effect of Floral Bud Removal on Performance of Soybeans1

Seed weight was increased such that the yield per plant of soybeans, Glycine max (L.) Merr., was not reduced when all floral buds were removed from any 1/3 section of the plant. When all floral buds were removed from either the upper or lower 2/3 of the plant, the increase in seed weight was not great enough to offset the reduction in the number of pods per plant, and, therefore, the yield per plant was reduced.Yield and number of pods per plant were reduced when all floral buds were removed from all the branches, but not affected when all floral buds were removed from the main stem. Seed weight was increased by both treatments. The vegetative parts of the plant without pods remained green until killed by frost; other parts of the plant senesced normally.Removal of floral buds (0 to 60 per plant at random over all nodes) had no effect on the number of pods per plant, seed size, or yield per plant. The protein content of the seed increased and oil content decreased as the number of floral buds removed increased.

Some Effects of the Continuous Removal of Floral Buds on the Growth of the Cotton Plant

Some Effects of the Continuous Removal of Floral Buds on the Growth of the Cotton Plant